How do you combine #(2x ^ { 2} + 7) - ( 8x ^ { 2} - 3)#?

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Answer 1 · 2018-01-26T04:05:15

The result is #-6x^2+10#.

#(2x^2+7)-(8x^2-3)#

Imagine that there is a #1# in front of that second part:

#(2x^2+7)-color(red)(1)(8x^2-3)#

Now you can use the distributive property with #-1# to open up the parentheses:

#(2x^2+7)color(red)-color(red)1*8x^2+color(red)-color(red)1*-3#

#(2x^2+7)-8x^2+3#

Now you can get rid of those other parentheses and simplify:

#color(blue)(2x^2)+color(red)7color(blue)(-8x^2)+color(red)3#

#color(blue)(2x^2)color(blue)(-8x^2)+color(red)7+color(red)3#

#color(blue)(-6x^2)+color(red)10#